N-(oxymethyl) derivatives of phosphonopolyamino-s-triazines used as flame retardants for cellulosic materials

ABSTRACT

There are disclosed N-(oxymethyl) derivatives of phosphonopolyamino-s-triazines, such as 2,4-bis-(hydroxymethyl)6-(0,0&#39;&#39;-diethylphosphonomethyl)-s-triazine and the corresponding 2,4-bis(methoxymethyl) derivative. These compounds are produced by reaction of the corresponding amine, e.g., 2,4-diamino-6(0,0&#39;&#39;-diethylphosphonomethyl)-s-triazine, with formaldehyde, either alone or in combination with an alkanol, such as methanol, in aqueous medium. The products are useful either alone or in combination with organo-nitrogen compounds as flame-retardant agents for cellulose. A durable treatment is obtained by insolubilization with acidic catalysts or hydrogen peroxide.

ilited States Patent Tesoro et a1.

N-(OXYMETHYL) DERIVATIVES OF PHOSPHONOPOLYAMINO-S- TRIAZINES USED ASFLAME RETARDANTS FOR CELLULOSIC MATERIALS lnventors: Guiliana Tesoro,Dobbs Ferry, N.Y.; Stephen B. Sello, Cedar Grove; Donald R.

Moore, Rutherford; Rudolf F. Wurster, Weehawken, all of NJ.

Assignee: J. P. Stevens & Co., Inc., New York, NY.

Filed: Apr. 15, 1970 Appl No.: 33,147

Related US. Application Data Division of Ser. No. 716,323, Mar. 27,1968, Pat. No. 3,551,422.

US. Cl ..8/116.3, 8/129, 8/116.2, 8/116 P, 106/15 FP, 117/137, 252/8.1,260/231 A Int. Cl. ..D06m 13/28, D06m 13/32, D06m 13/44 Field oiSearch..8/116.3, 116 P, 116.2; 117/137; 106/15 FP; 260/231 A [56] ReferencesCited UNITED STATES PATENTS 3,011,998 12/1961 DAlelio ..8/116.3 X3,050,522 8/1962 Coates et a1. ..8/l16.3 3,551,422 12/1970 Tesoro et a1...8/1 16.3

Primary ExaminerGeorge F. Lesmes Assistant ExaminerJ. CannonAtt0rneyBernard Marlowe and Kenyon & Kenyon Reilly Carr and Chapin [5 7]ABSTRACT There are disclosed N-(oxymethyl) derivatives ofphosphonopolyamino-s-triazines, such as2,4-bis-(hydroxymethyl)-6-(0,0'-diethylphosphonomethy1)-s-triazine andthe corresponding 2,4-bis(methoxymethyl) derivative. These compounds areproduced by reaction of the corresponding amine, e.g.,2,4-diamino-6-(0,0'-diethy1phosphonomethyl)-striazine, withformaldehyde, either alone or in combination with an alkanol, such asmethanol, in aqueous medium. The products are useful either alone or incombination with organo-nitrogen compounds as flame-retardant agents forcellulose. A durable treatment is obtained by insolubilization withacidic catalysts or hydrogen peroxide.

6 Claims, 1X0 Drawings N-(OXYMETHYL) DERIVATIVES FPHOSPIIONOPOLYAMINO-S-TRIAZINES USED AS FLAME RETARDANTS FOR CELLULOSICMATERIALS This is a division of application Ser. No. 716,323, filed Mar.27, 1968 and now U.S. Pat. No. 3,551,422.

DESCRIPTION OF THE INVENTION This invention is concerned with compoundscomprising at least one phosphono radical and anN-(oxymethyl)amino-striazine radical. More particularly, this inventionrelates to phosphono-substituted polyamino-s-triazines. In a furtherembodiment, this invention is concerned with the use of such compoundsas flame-retardant agents for cellulose.

The compounds of the present invention are represented by the generalformula:

wherein R is lower alkyl, halogen-substituted lower alkyl or0,0-di-lower alkylphosphono-substituted lower alkyl; R is a divalent ortrivalent saturated, acyclic organic radical consisting of from one toabout carbons and up to two heteroatoms of the group amine or hydrazinenitrogen, ether oxygen and thioether sulfur, said radical being bondedto phosphorus from carbon; each of R and R is hydrogen or lower alky1;ais an integer having a value of 1 or 2, and is 1 when R isphosphono-substituted alkyl; b is an integer having a value off) or i;and n is an integer having a value offrom l to 4.

By the term lower alkyl" is meant a linear or branched chain alkyl groupof up to about 10, preferably about 6, carbons, such as methyl, ethyl,n-propyl, isopropyl, tert-butyl and the like, with methyl and ethylbeing preferred. By the term lower alkylene" is meant a divalent linearor branched alkylene group of up to about 10, preferably about six,carbons, such as methylene, ethylidene, ethylene, propylidene,isopropylidene, trimethylene, tetramethylene, methyl-substitutedtrimethylene and methyl-substituted tetramethylene groups, and the like.By the term lower alkanetriyl" is meant a trivalent linear or branchedsaturated acyclic hydrocarbon radical of up to about 10, preferablyabout six, carbons, such as methylidyne, ethylidyne, ethylidenyl,1,2,3-propanetriyl and the like. By the term oxymethyl is meant analkoxymethyl or hydroxymethyl group. By the term halogen" is meant ahalogen having an atomic number of 17 to 53, inclusive, (chlorine,bromine and iodine) with chlorine and bromine being preferred.

As is apparent from the foregoing, the N-(oxymethyl) derivativescomprise an s-triazine nucleus substituted on one nuclear carbon thereofwith a phosphono-containing radical and on each of the remaining nuclearcarbons with an amino or substituted amino group, there being at leastone substituted amino group and at least one N-(oxymethyl)-substituent.The portion of these compounds exclusive of the phosphono-containingradical will be referred to hereinafter as an N-(oxymethyl)-substituted2,4-diamino triazine residue. Illustrative of these residues areradicals such as 2-amino-4- (hydroxymethylamino)-s-triazin-6-y1,2,4-bis-(hydroxymethylamino)-s-triazin-6-yl, 2-(hydroxymethylamino)-4-[bis(hydroxymethyl)amino]6-yl,2,4-bis[bis(hydroxy-methyl)aminoJ-s-triazin-6-yl,2,4-bis(methoxymethylamino)-s-triazin-6-yl,2,4-bis(isopropoxymethylamino)-s-triazin-6-yl,2,4-bis(tert-butoxymethylamino)-s-triazin-6-yl, Z-(N-hydrOXymethyl-N-methylamino)-4-(dirnethylamino)-s-triazin-6-yl, and the like.

The compounds of this invention also may be categorized according to thenature of the phosphono-containing radical. In the ensuing discussionthe N-(oxymethyl)-substituted 2,4- diamino triazine residue will not beredefined, but will be referred to simply as the triazine residue. Itwill be understood, however, that the various phosphono-containingradicals to be disclosed either specifically or generally can beattached to any of the previously disclosed triazine residues.

A preferred class of compounds within the scope of F ormula (1) is thatrepresented by the formula:

wherein R is as defined above; each of R and R is alkylene of not morethan about 10 carbons; R is hydrogen, lower alkyl, or0,0'-substituted-phosphonoalkyl of the formula (R O),P(O)R-; R" ishydrogen or lower alkyl; R' is alkylene or alkanetriyl of not more thanabout 10 carbons; R is lower alkyl; Y is oxy, thio, imino or loweralkylimino; Z is the N-(oxymethyl)-substituted triazine residue ofFormula (I); and each of r, s, r, u and v has a value of 0 or 1; withthe provisos that the total carbons in R, R and R is not more than about10; the sum of each of r+.r, r+u and t+u is l; r is 0 when R isphosphonoalkyl; and u is O and R is hydrogen or alkyl when R isphosphonoalkyl.

Preferred compounds are those wherein no hydrocarbon radical (alkyl,alkylene or alkanetriyl) has more than four carbons, with thosecontaining from one to two carbons (methyl, methylene, methylidyne,ethyl, ethylene, ethylidene, ethylidenyl, ethylidyne) being particularlypreferred. In addition Y is desirably imino or alkylimino, and R isdesirably hydrogen.

The compounds of Formula II may be further divided into severalsubclasses. The first subclass comprises the monophosphonates of thegeneral formula:

( )2 w 2w (Ill-A) wherein R", w and Z are as defined above. B.(Dialkylphosphono )alkylheteroand[(Dialkylphosphono)alkylhetero]alkyl-substituted triazines of theformula:

( )2 u- 2w Z (lll-B) wherein R, R, Y, w and Z are as defined above. C.(Dialkylphosphono)alkylhydrazinoandDialkylphosphono)alkylhydrazinoJalkyl-substituted triazines of theformula:

wherein R, R", R", R, w and Z are as defined above.

D. [(Dialkylphosphono)alkylhetero1alkylaminoand{(Dialkylphosphono)alkylheterolalkylamino alkyl-substituted triazines ofthe formula:

RID

wherein R, R, R, R, w and Z are as defined above.

A second major subclass of phosphono-substituted triazines comprises thepolyphosphonates, which can be further subdivided into three classes.The first of these classes comprises the0,0-bis(0,0'-dialkylphosphonoalkyl)phosphono-substituted triazines ofthe formula:

wherein R, R, R, R, R, r, s, t, w, and Z are as defined above and R isalkylene.

The alkyl groups defined by R", R and R are preferably methyl or ethyl;the alkylene groups defined by R, R" and R are preferably ethylene, andw is preferably 0 when t is 1. This class, like the class of Formula(III), can be further subdivided in accordance with the complexity ofthe linkage between the phosphono and triazine radicals.

The second grouping of the polyphosphonates comprises thebis(dialkylphosphono)alkyl-s-triazines of the formula:

wherein R and Z are as defined above and R" is alkanetriyl, especiallyfrom one to two carbons.

The third grouping of polyphosphonates comprises the N,N-bis-[(dialkylphosphono)alkyl]aminoorN,N-bis-[(dialkylphosphono)alkyl]aminoalkyltriazines and thecorresponding phosphonoalkyl-substituted hydrazines of the formula:

e 0 RHh-N N 0 wH2wZ (V id wherein R', R", R", s, w and Z are as definedabove. The alkyl groups defined by R" and R are preferably methyl orethyl; R is preferably ethylene and w is preferably 0.

Illustrative examples of these compounds include N-(oxymethyl)derivatives of:

2,4-Diamino-6-(0,0'-dimethylphosphono)-s-triazine;2,4-Diamino-6-(0,0'-diethylphosphono)-s-triazine;2,4-Diamino-6-(0,0-diisopropylphosphono)-s-triazine;2,4-Diamino-6-(0,0'-dibutylphosphono)s-triazine; 2,4-Diamino-6-(0,0'-diethylphosphonomethyl)-s-triazine;2,4-Diamino-6-[2-(0,0-dimethylphosphono)ethyl]-striazine;2,4-Diamino-6-[N-(0,0'-diethylphosphonoethyl)-amino]- s-triazine;2,4-Diamino-6-[ 2-(0,0-diethylphosphono )ethoxy1-striazine;2,4-Diamino-6-[ 2-(0,0'-diethylphosphono)ethyl-thio]-striazine;2,4-Diamino-6-{N-[ l -(0,0'-diethylphosphono )-butyl]amino}-s-triazine;2,4-Diamino-6-[ N-ethyl-N-(0,0-diethylphosphonoethyl)amino ]-s-triazine;2,4-Diamino-6-{N-[2-(0,0'-diethylphosphono)-ethyl]aminomethyl}-s-triazine;2,4-Diamino-6-{N-[2-(0,0-diethylphosphono)- ethyl]hydrazino}-s-triazine;2,4-Diamino-6-{2-[2-( 0,0'-diethylphosphono)-ethylamino]ethylamino}-s-triazine; 2,4-Diamino-6-{2-[2-(0,0'-diethylphosphono)-ethyloxy]ethylamino} -s-triazine;2,4-Diamino-6-[0,0-bis(diethylphosphonomethyD- phosphono1-s-triazine;2,4-Diamino-6-[0,0-bis(diethylphosphonoethyly phosphono]-s-triazine;2,4-Diamino-6-[0,0-bis( diisopropylphosphonoethyl)phosphonomethyl]-s-triazine;2,4-Diamino-6-{N-[0,0'-bis(diethylphosphonoethyl)phosphonoethyl]aminoethyl}-s-triazine;2,4-Diamino-6-[bis(0,0'-dimethylphosphono)-methyl1-striazine;2,4-Diamino-6-[ l ,2-bis(0,0-diethylphosphono)-ethyl]-striazine;

2,4-Diamino-6-[ 2,2-bis( diethylphosphono )ethyl]-striazine;

2,4-Diamino-6-[N,N-bis(0,0'-diethylphosphonoethyl)amino]-s-triazine;

2,4-Diamino-6-[N,N-bis(0,0-dibutylphosphonoethyl)-amino-methyl1-s-triazine;

2,4-Diamino-6-{N,N-bis[2-(0,0'-diethylphosphono)- ethyl 1 hydrazine}-s-triazine.

The (oxymethyl) derivatives of phosphono-substituted polyamino triazinesof this invention are readily prepared by a variety of methods fromknown starting materials by first synthesizing the correspondingphosphono-substituted polyamino triazine followed by conversion of theamine to the N-(oxymethyl) derivative.

The aminophosphonotriazines are produced by a variety of knowntechniques. The first and most general technique employs theArbuzovReaction wherein a phosphite is reacted with a halogen-substitutedcompound to form a phosphonate as illustrated by the following:

Reaction A:

wherein all variables but X and Z are as previously defined, X ishalogen and Z is a 2,4-diamino-s-triazin-6-yl radical having onlyN-alkyl groups as substituents.

Suitable phosphites include trimethyl phosphite, triethyl phosphite,triisopropyl phosphite, tri-tert-butyl phosphite, trihexyl phosphite,tris(2-chloroethyl) phosphite, tris(2- bromoethyl) phosphite and thelike.

Suitable halogenated starting materials include 2,4-diamino-6-chloro-s-triazine, 2,4-diamino-6-bromo-s-triazine,2,4-diamino-6-chloromethyl-s-triazine, 2,4-diamino-6-(2,2-dibromoethyl)-s-triazine, 2,4-diamino-6-( 1,2-dibromoethyl)- s-triazine,2,4di-amino-6-( 2-chloroethylamino )-s-triazine, and the like.

This reaction is readily effected by admixing the phosphite, preferablyin stoichiometric excess, with the halogen-containing triazine andheating the resulting mixture at elevated temperature, suitably thereflux temperatures. After completion of the reaction excess phosphitecan be distilled off.

In a second procedure, phosphonoalkylamino derivatives are obtained byreaction of an amine and a halogen-containing wherein all variables areas previously defined.

Suitable triazines include those discussed with reference to Reaction A,above. Aminoalkylphosphonates which can be employed include diethylaminomethylphosphonate, diethyl l -aminoethylphosphonate, diethyll-aminopentylphosphonate, diethyl 2-( 2-aminoethylamino)ethylphosphonate, diethyl 2-( 2- aminoethyoxy)-ethylphosphonate, diethyl 2-( 2- Reaction C:

wherein R is as previously defined and R is hydrogen or lower alkyl.

Related to this last reaction is one in which melamine is reacted withan aldehyde and a phosphite to yield an N- (phosphonoalkyl) derivative:

Reaction D:

(ROMP (O)(|3HNHC:N3(NH2):

wherein R and R are as defined above. Still another procedure comprisesthe reaction of an alkyl (0,0'-dialkylphosphono)alkanoate withbiguanide:

Reaction E:

in addition, 3-(dialkylphosphono)propionitrile is reacted with acyanoguanidine to produce2,4-diamino-6-{2-(0,0'-dialkylphos-phono)ethyl]-s-triazines.

Reaction G:

Still another technique comprises the well known reaction wherein acompound containing an activated vinyl group is reacted with a compoundcontaining active hydrogen. Thus, a vinylphosphonate may be reacted witha substituted triazine:

Reaction H:

(RO)zP(O)CH=CHz H(YR NNR 1 L1 J R c (RO)gP(O)CH1CH:(YR )Y N NR 1 l Jwherein all variables are as defined above, with the proviso that atleast one ofr and t is l.

The reactants employed in the various reactions outlined above aregenerally known compounds. The reactants containing one or more heteroatoms in the chain, although not always known compounds, are readilysynthesized from known compounds by a known procedure. For example, thetriazine derivatives employed in Reaction H wherein there are two heteroatoms in the chain are obtained by reaction of hydrazine, a diamine, ora hydroxy amine with a halogen-substituted triazine:

Phosphonates useful in the reaction of Reaction B are obtained, forexample, by reaction of ethylenimine with a 2-substitutedethylphosphonate in accordance with the equation:

The amine precursors of the bis(dialkylphosphonoalkyl)-phosphono-substituted compounds of Formula (IV) may be prepared by anyof the foregoing reaction sequences if desired. It is preferred,however, to employ one of the foregoing techniques to produce abis(haloalkyl)phosphono-substituted polyamino-s-triazine of the formula:

wherein all variables are defined above.

These compounds are then reacted with a trialkyl phosphite (Arbuzovreaction) to produce the bis(dialkylphosphonoalkyl)phosphono-substitutedderivative.

The N-(oxymethyl) derivatives of this invention are synthesized from thecorresponding amines by reaction of the amine with formaldehyde. Ingeneral, an aqueous dispersion (e.g., a slurry) is made of the ester ofthe 2,4-diamino-6- phosphono-s-triazine, using preferably 0.1 to lkilogram of water per mole of diamino compound. If an (alkoxymethyl)derivative is desired rather than a (hydroxymethyl) derivative, theappropriate alkanol is added at this point. While the dispersion is keptpreferably at 10 to 70 C., formaldehyde is added. The amounts offormaldehyde and alkanol are selected on the basis of the degree ofN-substitution desired, i.e., from one to four N-(oxymethyl) groups canbe introduced on the diamino compound by employing the appropriatecorresponding ratio of formaldehyde (and alkanol) to diamino compound.It is convenient to add the formaldehyde in the form of a strong aqueoussolution, such as the 30 to 40 percent solution available commercially.A small amount of a base may be used as a catalyst to increase thereaction rate (as 4 to 40 ml. of l-normal sodium carbonate per mole ofdiamino compound). A reaction period of 0.5 to 3 hours is usuallyadequate for a catalyzed reaction, whereas 5 to 30 hours is usuallyneeded without a catalyst. The N-(oxymethyl) deriva tive may be isolatedby evaporating the reaction solution. Ordinarily the product will be amixture of derivatives having varying degrees of N-(oxymethylation). Asingle product can be obtained, however, by employing a sufficientexcess of formaldehyde (and alkanol) to ensure oxymethylation at allavailable amino hydrogens.

The compounds of this invention, because of the presence of variousfunctional goups, have utility as reaction intermediates for a varietyof products. They are of particular utility, however, as flame-retardantagents for cellulose.

It has long been known that flame-retardant properties may be impartedto cellulose, particularly in a textile form, by treatment withphosphoric acid or compounds capable of forming phosphoric acid or itsanhydride on burning. However, these methods are generally unacceptabledue to serious degradation of the cellulose as well as lack ofdurability of the treatment.

More recently treatments employing organophosphorus compounds have beendeveloped in an effort to provide flame retardance without concurrentdamage to the cellulose and to render the phosphorus-containing agentresistant to removal during laundering. Although many of thesetreatments are in commercial use today, none has been completelysuccessful due to the high cost of the organophosphorus compound and thehigh degree of add-on of organophosphorus compound required to provideflame-retardant properties.

Still more recently G. C. Tesoro has discovered that organic nitrogen isa synergist for phosphorus-induced flame retardance in cellulose, andthus allows the use of reduced amounts of organophosphorus compound. Forexample, when 6- to l-ounce cotton fabric is treated with anorganophosphorus compound little or no flame-retardant efiect isobserved until at least about 1.5 weight percent phosphorus,

based on cellulose, is present, and acceptable flame-retardantproperties are not achieved until the phosphorus content is at leastabout 2 percent. By incorporating sufficient organic nitrogen into thetreatment, however, excellent flame-retardant properties can be obtainedat phosphorus contents as low as about 0.2 weight per cent, despite thefact that organic nitrogen compounds alone are not flame retardantagents. In such treatments the amount of nitrogen which is requiredincreases as the phosphorus content decreases.

Previously the nitrogen-phosphorus ratio necessary to achieve adesirable degree of flame retardance at low phosphorus contents could beobtained only through the use of a mixture of reagents, and in manycases the treatment was not durable, i.e., resistant to laundering. Inaddition many of the reagents, especially the phosphorus-containingcompounds, were soluble only in organic media, thus presenting potentialhealth hazards as well as increasing the expense of the process.Finally, the previously evaluated reagents frequently had low phosphorusand nitrogen contents, thus requiring a high degree of add-on, withattendant adverse effect on physical properties such as hand, to achieveflame-retardant properties.

The N-(oxymethyl) phosphono-substituted polyamino-striazines of thisinvention are well suited for use as flame-retardant agents forcellulose. They contain a large proportion of nitrogen and phosphorus(frequently 30 weight percent or more) and a high atomic ratio ofnitrogen to phosphorus (up to 5:l or even higher). As a result, they canbe employed alone (withoutother additives) at a low total add-on toachieve excellent flame-retardant properties. Moreover, they are solublein water and thus do not require the use of organic media. They arereadily insolubilized to provide an extremely durable treatment.Finally, the insolubilized compounds and flame-retardant treatmentsresist laundering even in the presence of hypochlorite bleach.

The flame-retardant treatment of this invention is efiected by treatmentof a cellulosic substrate with an aqueous solution of the N-(oxymethyl)phosphono polyamino triazine, which can be the aqueous solution in whichit is prepared, by insolubilization of the agent on the substrate.

The concentration of the phosphono triazine in the aqueous solution isnot critical, and will depend upon the amount required to achieve thedesired degree of flame retardance and the manner in which the agent isto be applied to the substrate. For textile fabrics, a convenient methodcomprises padding the fabric to about 100 percent wet pickup. In suchcases concentrations of from about to about 25 weight per cent of theN-(oxymethyl) phosphono-substituted polyaminos-triazine in the aqueoussolution have been found suitable.

In addition to the agent of this invention, the aqueous solution willalso contain a catalyst which promotes insolubilization of the triazineagent. Suitable insolubilization agents are those which can insolubilizeN ,N,N -tris(hydroxymethyl)- melamine, such as hydrogen peroxide oracidic catalysts.

When hydrogen peroxide is employed, it is present in the aqueoussolution in an amount of from about 0.05 to about 0.5 weight percent,and after padding, the wet fabric is partially dried and then steamed,usually for from about 5 to about 10 minutes, and then rinsed and dried.

Acidic catalysts which are suitable for use with the present inventioninclude the ammonium salts of mineral acids such as hydrochloric,sulfuric, phosphoric and nitric; amine salts of mineral acids; thechlorides and nitrates of zinc and magnesium; acid fluoride salts; zincfluoroborate and others of this type. In addition to the above salts,nonvolatile acids of moderate strength such as citric acid and sodiumhydrogen sulfate may also be employed.

Some of the above acidic catalysts, such as magnesium chloride, arelatent acid catalysts, and provide acidic conditions upon heating. Whensuch catalysts are used the treated material must be heated to thetemperature level necessary for production of the requisite acidconditions. Such latent acid catalysts are ordinarily employed in aconcentration of from 0.5 to about 5 weight percent.

If the acidic catalyst is of the type that does not require heating toform hydrogen ions, for example, those catalysts which form hydrogenions upon hydrolysis or ionization in water, the catalytic activity isgenerally controlled by appropriate choice of the pH of the treatingsolution. In such instance, the pH of the treating solution should behigher than about 3.5 since the use of acid catalysts yielding asubstantially lower pH may adversely affect the cellulosic materialbeing treated.

After padding with an acidic catalyst, the wet fabric is ordinarilydried at a moderately elevated temperature, for example 50 to C., andthen cured by heating at more elevated temperatures, such as from aboutC. to about C. The curing time at these temperatures will range fromabout 1 to about 20 minutes, and is inversely related to temperature.

The chemical structure of the resulting product is not entirely known.In the case of the acid-catalyzed reaction, at least a portion of thetriazine compound is insolubilized by reaction of the N-(oxymethyl)groups with cellulosic hydroxyls as illustrated by the equation:

In addition, reaction may occur between the N-hydroxymethyl groups oftwo different compounds:

When n in Formula I is at least 2, polymers will be formed. In the caseof the peroxide-catalyzed insolubilization the reactions which occur areeven less clear, but probably include those discussed above, as well asother reactions. Regardless of mechanism, however, theN-oxymethylamino-phosphonosubstituted triazines do become insolubilized,as is evidenced by the extreme durability of the treatment.

In addition to flame-retardant agent and insolubilization agent, thesolution may contain other agents which can be employed to improve ormodify cellulosic substrates. For example, when cellulosic textilematerials are treated in accordance with this invention, the bath maycontain such additives as sof- .teners, optical brighteners, and thelike.

Although the phosphono-s-triazines are excellent flame-retardant agentswhen employed above, they may be employed in combination with otherflame retarding agents. In addition their eflicacy as flame retardingagents may be improved by employing them in combination withorgano-nitrogen compounds. In particular, the use of additionalorgano-nitrogen compounds permits the use of smaller amounts of thephosphonotriazines.

Suitable compounds for this purpose include organic compounds having acarbon-nitrogen linkage, with compounds wherein nitrogen is in the formof an amine or an amide group being preferred. Amide forms include thecarboxamide forms, with the carboxamide form being preferred.Particularly preferred nitrogen-containing compounds are thosecontaining the linkage represented by the partial formula:

and sulfonamide wherein each A, when taken separately, is oxo, thioxo orimino; R is a divalent hydrocarbylene, especially alkylene, radical ofone to five carbons; R and R" each are hydrogen, amino, cyano orhydrocarbyl or hydroxyhydrocarbyl, especially alkyl or hydroxyalkyl, ofup to about 5 carbons; each ofy and z has a value ofO or 1; and x is aninteger having a value of at least and preferably of 0 or I.

Illustrative compounds include urea, thiourea, guanidine, dicyandiamide,biguanide, semicarbazide, carbohydrazide, biurea, l,l'-ethylenediurea,l,3-bis(hydroxymethyl)urea and the like.

Another class of nitrogen compounds are those heterocyclic compoundsofthe formula:

wherein A is as defined above; R is a divalent hydrocarbyl group,preferably alkylene, of up to 6 carbons, which, when taken with theNC(A)N grouping, forms a fiveto six-membered heterocyclic ring; and eachR" and R is hydrogen, lower hydrocarbyl, or lower hydroxyhydrocarbyl(e.g., lower alkyl or hydroxy lower alkyl of up to six carbons).

Illustrative examples include 2-imidazolidin0ne, 2- imidazolidinethione,Z-iminoimidazolidine, 1,3-diethyl-2- imidazolidi-none,I,3-bis(hydroxymethyl)-2-imidazolidinone and the like.

Still another and an especially preferred class of usefulnitrogen-containing heterocyclic compounds are the s-trian'nederivatives of the formula:

Wherein each R", independently, is hydrogen, lower hydrocarbyl orhydroxy or alkoxy lower hydrocarbyl, (e.g., lower alkyl or lower alkoxylower alkyl).

Illustrative compounds include melamine, N,N,N- trimethylmelamine, N,N,N-tris(hydroxymethyl)melamine, hexakis(methoxymethyl)melamine and thelike, with those wherein at least one R of each amino group ishydroxymethyl or lower alkoxymethyl being particularly preferred.

In addition to these compounds, polyalkyleneamines, preferablycontaining at least four nitrogen atoms per molecule, wherein thealkylene group has from two to about six carbons, are highly desirablenitrogen compounds.

In this embodiment, the cellulose can be treated with theorgano-nitrogen compound simultaneously with or before or aftertreatment with the s-triazine compound. The technique employed intreating the cellulose with the organo-nitrogen compound is not a partof this invention, and in general will be known to those of ordinaryskill in the art. It is preferred, however, that the organo-nitrogencompound, at least in the form in which present in the final product, berelatively nonvolatile, such as a compound having a normal boiling pointabove about 200 C. and be resistant to removal by laundering. Particularly preferred organo-nitrogen compounds are those which arewater-soluble for ease of application but which can be renderedinsoluble, as by polymerization or reaction with the cellulose.

The amounts of phosphorus and nitrogen which are present on thecellulosic substrate are not critical to this invention, provided thatthey are at least sufficient to impart flame retardance. The specificamounts necessary for this purpose will depend upon the substrate andthe standard of flame retardance employed.

For example, the substrate greatly influences the degree of flameretardance both on a molecular level and a macroscopic level. Thus,certain molecular forms of cellulose, for example, rayon, are moreflammable than other forms, such as cotton. Similarly, certain physicalforms, for example fibers or yarns, are more flammable than others, suchas fabrics woven from the same fibers or yarns. Again, the density orsurface area per unit weight affects flammability, lightweight fabrics(e.g., 4 ounces per square yard) being more flammable than heavier(e.g., 8-ounce) fabrics. In addition, thick substrates will require lessagent on a weight per weight basis than a thin substrate.

Similarly, the required amounts of phosphorus and nitrogen will dependupon the particular standard of flame retardance employed. In thisregard, it should be noted that no universal test has been devised todetermine flame retardance. Indeed, there is no generally-accepteddefinition of the term. In most cases the article to be evaluated istested under actual or simulated conditions of intended use, and thestandard of flame retardance is related only to that use. As a result,the correlation of the degree of flame retardance obtained by a givenflameretardant agent on one cellulosic form with that obtained on adifferent cellulosic form based upon the teachings of the prior art isdifficult, if not impossible.

As employed in this application, however, the term flame retarding" issynonymous with self-extinguishing. That is, flame-retardant propertiesobtain when, although the surface or article may burn when in directcontact with a flame source, the flame will go out once the source isremoved rather than continue to propagate. One commonly employed testfor determining flame retardance, as employed in this sense, is theso-called vertical flame test, which is generally applicable only toplanar cellulose forms, for example cellulosic fabrics, whether bonded,knitted or woven, paper sheets and the like. In this test, a fixed flamesource is applied to the bottom edge of a vertically held strip of thematerial for a given period of time and then removed. The length of thecharred or burned portion, i.e., the char length, of the sample ismeasured, and is the index of flame-retardant properties. On the otherhand, the flame-retardant properties of wood treated to reduceflammability are frequently measured by the crib" test (ASTM E -50),herein 24 specimen pieces (1% inch :6 inch X 3 inches) are subjected toa flame at 315 1- 8 C. for minutes, and the per cent weight loss andduration of glow are recorded. Still other tests have been devised forother forms of cellulose.

In the above-mentioned vertical flame test, it has been generallyobserved that the char length will be either less than about half of thesample, or the entire sample will be consumed. As a result, whenemploying a 10- or 12-inch by 2%- inch sample, flame-retardantproperties are generally considered adequate if the char length is lessthan an arbitrarily selected value, generally 4% to 6% inches, dependingupon fabric weight. As applied to an 8-ounce, woven cotton twill fabric,a char length of less than 5 inches is taken to signify an acceptabledegree of flame retardance. To achieve this degree of flame retardancewith 8-ounce cotton fabrics, the product produced in accordance withthis invention should contain nitrogen in an amount equal to at leastthe value of the expression 6-2P where P is the weight percentphosphorus, based upon cellulose, in the range of from about 0.2 toabout 3 percent. It should be noted that this expression is valid onlyfor the specific substrate, although similar inverse relations will beobserved with other substrates.

The treatment of this invention is applicable to cellulose in bothtextile and non-textile forms. Textile forms include filaments, fibers,yarns and fabrics (whether woven or nonwoven, such as bonded andknitwear fabrics.) The cellulose can be from any source, including suchnatural sources as seed hairs such as cotton, bast fibers such as flax(linen), ramie, jute or hemp, as well as synthetic sources, for exampleregenerated cellulose such as rayon, or modified rayon, and partiallyacylated cellulose such as partially acetylated cellulose. Nontextileforms include both fiber and non-fiber forms, such as wood, paper andcellulosic film, whether in native, regenerated or partially substitutedform. The treatment of this invention, although of most benefit forwholly cellulosic materials, is generally useful for cellulosicmaterials containing at least about 30 weight percent cellulose, such asblended yarns and fabrics.

The following examples are illustrative. In the examples the followingtest methods were employed:

1. Laundering: Home-type washer, 5-pound load, full cycle, 60 C., withsynthetic detergent.

2. Laundering with Hypochlorite Bleach: 0.5 pint of commercial bleach(5.25 percent solution of sodium hypochlorite) was added per 16 gallons,thereby diluting the NaOCl to 0.02 percent during laundering.

3. Shrinkage in Laundering (in The fabric was conditioned for at least 4hours (relative humidity 65 i 2 percent at 21 1 C.), and markings wereapplied 8 inches apart in both warp (W) and filling (F) directions. Thenthe fabric was laundered and tumble dried, after which the fabric wasre-conditioned for at least 4 hours and the distances between markingswere remeasured.

4. Flex Abrasion Resistance (in cycles, in the warp direction): ASTM D 1175 6lT; 0.5-pound head weight and 2- pound toggle tension on Stoll FlexAbrader.

5. Tensile Breaking Strength (in pounds, in the warp direction):One-inch ravelled strip method; ASTM D 1682 59T.

6. Damage Caused by Retained Chlorine: Percentage of tensile strengthlost between scorched and unscorched strips; AATCC 92-1962.

7. Vertical Flame Test (Char Length in Inches): AATCC 34-1952. Modifiedtextile fabrics having char lengths of 5 inches or less have acceptablefire resistance. BEL" means burned the entire length.

8. whiteness Rating: AATCC l 10-1964-9.

9. Nitrogen: Determined by Kjeldahl digestion followed by either (1)Nessler colorimetry, or (2) distillation as ammonia followed bytitration.

10. Phosphorus: Determined by combustion using the Schoniger techniquefollowed by colorimetry employing a molybdenum blue complex; or byKjeldahl digestion followed by colorimetry employing acetone-water tointensify the phosphomolybdate color.

EXAMPLE I A mixture of 10 grams of2,4-diamino-6-(chloromethyl)-striazine and 20 milliliters of triethylphosphite was heated at reflux temperature for 11 hours in a flaskequipped with a reflux condenser. Unreacted triethyl phosphite was thendistilled off in vacuo and the concentrated product was recrystallizedfrom methanol to yield 3.2 grams of 2,4-diamino-6-(0,0'-diethylphos-phonomethyl)-s-triazine, m.p. 223 C.

Analysis: Calculated for C H N O P: C, 36.8%; H, 6.1%; N, 26.8%; P,11.9%. Found: C, 36.9%; H, 6.2%; N, 26.9%; P, 11.7%.

The assigned structure was confirmed by infrared analysis. In athin-layer chromatograph using silica gel 6" (with a binder), the R,-value was 0.26 i 0.04 for the ratio of the distance travelled by thesolute to the distance travelled by the solvent, the solvent beingl-butanol: methanol 4:1 by volume.

A slurry was made from 120 grams (0.46 mole) of 2,4-diamino-6-(0,0'-diethylphosphonomethyl)-s-triazine and 160 millilitersof distilled water. While the slurry was kept at 20 C., a total of 82grams of an aqueous 37 percent solution of formaldehyde (1.0 mole) wasadded during a 30-minute period. The mixture was heated to 62 C., and asolution resulted. The solution was stirred for 35 minutes longer andallowed to cool. Analysis of the reaction mixture for unreactedformaldehyde by means of hydroxylamine hydrochloride indicated that aconversion of 85 percent had occurred. That is, on the average, 1.7moles of formaldehyde had reacted per mole of2,4-diamino-6-(0,0'-diethylphosphonomethyl)-striazine. The solutionweighed 370 grams, and theoretically 40.5 percent of it was the desiredadduct. Evaporation to constant weight in high vacuum showed a solidcontent of 40 percent.

Analysis: Calculated for C H N O (CH O), -,:P, 9.65%; N, 21.8%; Bound CHO, 18.0%. Found: P, 9.45%; N, 22.1%; Bound CH O, 18.6.

The infrared spectrum in conjunction with the analytical valuestabulated above confirmed that the product was a mixture ofN-(hydroxymethyl) derivatives of 2,4-diamino-6-(0,0-diethylphosphonomethyl)-s-triazine, such as the bis(hydroxymethyl)and mono(hydroxymethyl) derivatives.

A percent cotton fabric (carded yarn sheeting weighing 4.0 ounces persquare yard having a thread count (warp filling) totaling 128)completely devoid of flame-retardant properties was padded to l 12percent wet pickup with a solution containing 20 weight per cent of thethus-produced N- (hydroxymethyl) product, 3 weight percent of an aqueous30 percent solution of an amine hydrochloride designated as Catalyst XRFby Onyx Chemical Co., Jersey City, N..l., and 77 weight percent water.The resulting fabric was dried at approximately 65 C., cured for 5minutes at approximately 163 C., rinsed in warm water and re-dried. Theresulting sample (A) bad a 17.4 percent weight gain, contained 1.62percent phosphorus and 3.29 percent nitrogen by analysis, and had a charlength in the vertical flame test was 5.6 inches.

A second portion (Sample B) of the sheeting was padded to percent wetpickup with a solution containing 14 weight per cent of theN-(hydroxymethyl) product, 3 weight percent of Catalyst XRF," 7 weightper cent of N ,N,N -tris(hydroxymethyl)melamine (TMM), and 76 weightpercent water, and then processed as described for Sample A.

A third sample (Sample C) of cotton sheeting was padded to l 13% wetpick-up with a composition containing 17.9 weight percent of theN-hydroxymethyl phosphonate ester; 3.0 weight percent of Catalyst XRF,9.9 weight percent TMM and 69.2 weight percent water.

A fourth portion of the cotton sheeting (Sample D) was pretreated by wetfixation of N ,N,N-tris(hydroxymethyl)- melamine (TMM) by padding to 106percent wet pickup with a solution containing 18 weight percent TMM, 1weight percent hydrogen peroxide (aq. 30 percent soln.) and 81 weightpercent water. The padded fabric was partially dried to a moisturecontent of 20 percent, held for 24 hours at room temperature, rinsed inan aqueous 0.1 percent solution of pl ,l ,3,3-tetramethylbutyl)phenoxynona(ethylenoxy)ethanol,

a nonionic detergent, and dried. The nitrogen content of this pretreatedfabric was 4.5 percent. Part of the pre-treated fabric was padded to 100percent wet pickup with a solution containing 16 weight percent of theN-hydroxymethyl phosphonate triazine product, 3 weight percent ofCatalyst XRF" (aq. 30% soln.), and 81 weight percent water. Processingwas similar to that employed for Sample A.

The procedure described for the preparation of Sample D was repeated ona fifth portion of the cotton sheeting (Sample E), with the variationthat the second pad bath contained 20 percent rather than 16 percent ofthe N-hydroxymethyl phosphonate triazine product. Data concerning allfive samples with respect to their evaluation are summarized in theaccompanying tables.

TABLE I Analytical Data Sample Weight Fabric Content.%

Gain. P N

TABLE II.-FLAME RETARDANCE [Char length, inches] 10 launderings 25launderings 50 launderings No laun- With Without With Without WithWithout Sample dering bleach bleach bleach bleach bleach bleach A 5.66.2 6.2 6.0 6.2 9.3 6.2 B 5.1 5.3 6.8 5.3 6.8 8.7 5.8 C 4.5 4.2 4.5 4.24.8 5.8 4.8 D 4.3 4.3 4.3 5.3 4.3 5.8 4.3 E. 4.1 4.4 4.2 4.4 4.7 5.6 5.0

TABLE III.-PHYSICAL PROPERTIES Shrinkage Tensile Flex Chlorine Whitenessstrength abrasion damage rating W F As can be seen from the foregoingdata, the finishes of this invention are extremely durable tolaundering, even in the presence of a chlorine-type bleach. As furtherevidence of stability, the char lengths of two portions of Sample Cwhich had been soaked for 4 and 8 hours, respectively, in an aqueoussolution of 0.2 weight percent sodium carbonate and 0.5 weight percentsodium salt of N-methyl-N-oleoyltaurine (28 percent active) maintainedat 95 C. were 7.0 and 8.7 inches. In addition, and unlike manynitrogenous fabric treatments, the samples treated in accordance withthis invention were not chloride retentive. Finally, the physicalproperties of the treated cotton fabric were satisfactory.

V diamino-6-(0,0-dimethylphosphonomethyl)-s-triazine EXAMPLE n A totalof 157 grams (0.80 mole) of dimethyl (ethoxycarboryl)methylphosphonatewas added dropwise during a 10- minute period to a solution of 96.8grams (0.96 mole) of biguanide in 2 liters of methanol. The resultingreaction mixture was kept at 60 to 65 C. for 0.5 hour, cooled to 20 C.and filtered. The solid was washed with methanol and dried in vacuo atroom temperature to yield 151 grams of 2,4-diamino-6-(0,0'-dimethylphosphonomethyl)-s-triazine melting at approximately 220C.

Analysis: Calculated for C H N O P: C, 30.9%; H, 5.15%; N, 30.1%; P,13.3%. Found: C, 30.8%; H, 4.53%; N, 30.5%; P, 12.9%. The assignedstructure was confirmed by infrared analysis and thin-layerchromatography.

A dispersion was made from 116 grams (0.5 mole) of 2,4-

and 300 grams of water. While the dispersion was kept at 60 C., a totalof grams of an aqueous 37 percent solution of formaldehyde (2.1 moles)and 2 milliliters of 2-normal sodium carbonate were added during aperiod of 0.5 hour. The pH went from 8.5 to 5 during the reactionperiod, and the final weight of the solution was 580 grams(theoretically 588 grams). Analysis of the solution indicated that 4.2percent of it was free formaldehyde, and that 5.2 percent was boundformaldehyde, corresponding to two N-(hydroxymethyl) groups per moleculeof the diamino s-triazine.

Analysis (of the solution): Calculated for C H N O P: N, 5.9%; P, 2.6%.Found: N, 6.0%; F, 2,4%.

A portion of the sheeting employed in Example 1 was padded to 107percent wet pickup with a solution of 20 weight percent of thehydroxymethylated triazine produced as described; 3 weight percentCatalyst XRF" (Aq. 30% soln.); and 77 weight percent water.

Subsequent processing was similar to that used in Example 1, i.e.,drying at 65 C., curing for 5 minutes at approximately 163 C., rinsing,and re-drying.

A second sample was prepared in a manner similar to that just described,except that the sheeting was padded to 102 percent wet pickup with asolution containing 1 weight percent hydrogen peroxide (as a 30 percentaqueous solution) in place of the Catalyst XRF," and after padding thesample was dried to a moisture content of 20 percent, steamed for 8minutes, and rinsed in an aqueous 0.1 percent solution of p- 1,1,3,S-tetramethylbutyl)phenoxynona-(ethylenoxy)- ethanol.

A third portion of the sheeting was padded to l 14 percent wet pickupwith a solution of 19.2 weight percent of the hydroxymethylaminotriazine, 3.0 weight percent Catalyst XRF (aq. 30% soln.), 9.6 weightpercent of N ,N,N tris(hydroxymethyl)melamine (TMM), and 68.2 weightpercent water, and then processed in a manner similar to that describedfor Sample 1.

A fourth portion of the sheeting was padded to 106 percent wet pickupwith 20 weight percent of the hydroxymetholamino triazine, 1 weightpercent of hydrogen peroxide (aq. 30% soln.), 10 weight percent ofTMM,and 69 weight percent water, and then processed in a manner similar tothat employed for Sample 2.

Part of the TMM pro-treated fabric prepared as described in the Sample Dof Example I (4.5 percent of which was bound nitrogen from wet fixationof TMM) was padded to 99 percent wet pickup with the compositionemployed to prepare Sample 1 of this example and processed in a similarmanner.

Data concerning all five samples with respect to treatment andevaluation are summarized in the accompanying table.

EXAMPLE 111 A total of 22 grams of diethyl 2-aminoethylphosphonate wasadded dropwise to a stirred suspension of 14.55 grams of2,4-diamino-6-chloro-s-triazine in 200 milliliters of water at 90 to 95C. The pH was kept at approximately 8.5 by the periodic addition of atotal of 57 milliliters of 2-normal aqueous sodium carbonate. Thoseconditions were maintained for 1.5 hours, by which time the rate ofconsumption of sodium carbonate had diminished markedly. The pH wasallowed to drop to 7.5, and a total of 3.6 grams of unreacted materialwas filtered off. Water was evaporated from the filtrate, and theorganic portion of the remaining material was dissolved in 200milliliters of hot 1-propanol and recrystallized by cooling to yield 9.0grams of 2,4-diamino-6-[2-(0,0'-diethylphosphono)-ethylamino]-s-triazine, melting at 232 C. A 2-gramportion recrystallized from 20 milliliters of 1- propanol melted at 233C.

Analysis: Calculated for C H N O P: C, 37.3%; H, 6.5%, N, 29.0%; P,10.7%. Found: C, 37.1%; H, 6.6%; N, 29.6%; 11.6%.

The infrared spectrum was consistent with the assigned structure.

Employing procedures similar to those described. in Example I, thisproduct is then reacted with formaldehyde to produce a mixedhydroxymethylamino derivative, which in turn, is employed either aloneor in combination with N ,N ,N -tris(hydroxymethyl)melamine, to rendercotton flame retardant.

EXAMPLE IV A mixture of 42.3 grams of 2,4-diamino-6-hydrazino-striazine,108.2 grams of diethyl vinylphosphonate, and 200 milliliters ofN,N-dimethylformamide was heated at 100 to 105 C. for 3 hours, and at120 to 130 for 7 hours, after which time the vinyl content of thereaction mixture had decreased to 0.5 percent. The solvent and excessdiethyl vi nylphosphonate were removed under high vacuum to leave ayellow, viscous residue representing an almost quantitative yield of2,4-diamino-6-(2,2-bis[2-(0,0'-diethylphosphono)ethyl]hydrazino)-s-triazine. By titration with hydrogenbromide in acetic acid using a pH meter to determine the end point, anequivalent weight of 481 was found (theory: 479).

-A slurry was made from 108 grams of this product, 94 grams of aqueous37 percent formaldehyde, and 50 grams of additional water. The mixturewas heated at 50 to 60 C. for hours while the pH was kept at 10 to 1 lby a small addition of aqueous 50 percent sodium hydroxide. Upon;analysis, the resulting aqueous solution had 12.29 percent totalformaldehyde and 1.85 percent free formaldehyde (hence 10.44 percentbound formaldehyde in N-hydroxymethyl groups), representing a 96 percentconversion to the tetramethylol derivative, namely,2,4-bis[bis(hydroxymethyl)amino]-6-{2,2-bis(0,0'-diethylphosphono)-ethyl]hydrazino}-s-triazine.

Employing procedures similar to those described in Example 1, a sampleof 100 percent cotton sheeting was padded to 108 percent wet pickup witha solution of 24 percent by weight of the thus-produced tetramethylolderivative; 3 percent by weight of Catalyst XRF (aq. 30 percent soln.);10 percent by weight of tris(hydroxyrr1ethyl)melamine; and 63 percent byweight of additional water. The resulting sample was then dried at 70C., cured for 5 minutes at approximately 163 C., rinsed, and re-dried.The sample had a weight gain of 22.5 percent and a char length of 5.8inches.

A second portion of the sheeting was padded to 107 percent wet pickupwith a solution of 30 percent by weight of the tetramethylol derivative;1 percent by weight of hydrogen peroxide (aq. 30 percent soln.); 10percent by weight of tris(hydroxymethyl)melamine; and 59 percent byweight of additional water. After processing of the sample by partialdrying and steaming as described in Example 11, the sample had a weightgain of 20.9 percent and a char length of 5.0 inches.

EXAMPLE V A 5-liter flask was charged with 537 grams (2.8 moles) of thediethyl ester of '3-(0,0'-diethy1phosphono)propionitrile, 277 grams (3.3moles) of l-cyanoguanidine, 3 liters of 1- propanol, and grams of sodiumethoxide. The mixture was heated at reflux temperature for a total ofapproximately 30 hours, after which period it was filtered hot. Uponcooling 2,4- diamino-6-[2-(0,0'-diethylphosphono)ethyl]-s-triazinecrystallized from the filtrate at room temperature. After a series ofrecrystallizations, a total of 415 grams (dry weight) of the2,4-diamino-6-[.2-(0,0-diethylphosphono)ethyl]-striazine was obtained,melting at 171-174 C. The infrared spectrum was consistent with theassigned structure. Analysis: Calculated for C H N O P: C, 39.0%; H,6.6%; N, 25.5%; P, 11.3%. Found: C, 38.6%; H, 6.0% N, 25.9%; P, 12.0%.

Aqueous 37 percent formaldehyde (830 grams, 10.2 moles) was adjusted topH 9 by the addition of aqueous 50 percent sodium hydroxide, and thecombination was added to 638 grams (2.32 moles) of the2,4-diamino-6-[2-(0,0'- diethylphosphono)ethyl]-s-triazine. Solution washastened by warming the mixture to 55 C. for approximately 6 hours,during which time the pH stayed between 8 and 9. Upon analysis, theresulting aqueous solution had 21.03% total formaldehyde and 5.54percent free formaldehyde (hence 15.49 percent bound formaldehyde inN-hydroxymethyl groups). The reaction solution was a 64 percentsolution, 79 percent converted to2,4-bis[bis-(hydroxymethyl)amino]-6-[2-(0,0'-diethylphosphono)ethyl]-s-triazine.

Employing procedures similar to those disclosed in Example 1, twosamples of cotton sheeting were padded to 92 to 94 percent wet pickupwith an aqueous solution containing 25 weight percent of the triazineand 3 weight percent Catalyst XRF," dried at 70 C. and cured at 163 C.for 5 minutes. After rinsing and drying one sample (Sample A) was paddedto 88 percent wet pickup with an aqueous solution containing 10 weightpercent TMM and 0.3 weight percent hydrogen peroxide. The second sample(B) was padded in a similar bath, except that the bath contained 15percent TMM.

A third sample (C) was treated in a manner similar to that for Sample B,except that the first bath contained only 15 percent of triazinecompound and the second padding was to 97 percent wet pickup.

Two additional samples (D and E) were padded to percent wet pickup witha bath containing 30 percent triazine, 10 percent TMM and 0.3 percentperoxide (D) or 15 percent triazine 15 percent TMM and 0.3 percentperoxide.

All five samples were partially dried to a moisture content of about20percent, and then steamed for 8 minutes, rinsed and dried.

Analyses of the resulting samples are summarized in Table V.

' After 25 launderings with persulfnte bleach at a level of0.25 pint per16 gallons.

The char lengths of the samples are summarized in Table VI.

TABLE VI 10 Launderings 2S Laundering:

Sample Laundry No Bleach BleachNo Bleach Bleach D 4.5 7.6 6.]BEI. BEL

EXAMPLE VI To 120 grams (0.84 mole) of 2,4-diamino-6-mercapto-striazineand one liter of warm water in a -liter flask was sodium hydroxide in200 ml. of water, followed by 2.5 liters of ethanol. The pH was adjustedto approximately 9.5 by the addition of dilute hydrochloric acid, andthen a total of 206 grams (0.84 mole) of diethyl 2-bromoethylphosphonatewas added. The reaction mixture was stirred and heated at refluxtemperature for approximately 14 hours, during which time the pH waskept at approximately 9.5 by addition of aqueous 50 percent sodiumhydroxide. The reaction mixture was filtered and the precipitate waswashed with ethanol. Solvent was evaporated from the main filtrate, andthe residual material was heated for a period of approximately 7 hoursin 3 liters of refluxing ethyl acetate to induce further reaction. Thereaction mixture was filtered, and the filtrate was cooled to inducecrystallization. A total of 145 grams (dry weight) of 2,4-diamino-6-[2-(0,0-diethylphosphono)ethylthiol-s-triazine was collected,a yield of 56.5 percent, melting at 145 to 147 C. The infrared spectrumwas consistent with the assigned structure.

In another run, the charge in a 2-liter flask consisted of 43.5 grams(0.264 mole) of 2,4-diamino-6-mercapto-striazine, 63.8 grams (0.26 mole)of diethyl 2-bromoethylphosphonate, 600 ml. of denatured alcohol 3A (5volumes of methanol for every 100 volumes of 95 percent ethanol), and100 ml. of water. The slurry was heated at reflux temperature for atotal of approximately 20 hours. After removal of grams of byproduct byfiltration, the filtrate was evaporated, and the residue was extractedby 3 liters of ethyl acetate. The hot filtrate was concentrated byevaporation. A total of 59 grams (dry weight) of2,4-diamino6-[2-(0,0'-diethylphosphono)- ethylthioLs-tn'azine wascollected, a yield of 74 percent,r melting at 144 to 147 C. Afterrecrystallization from ethyl acetate, it melted at 146.5 to 148 C.

Analysis: Calculated for C l-l N O PS: C,35.2%; H,5.86%; N,22.8%;S,10.1%. Found: C,36.8%; H,5.60%; N,22.8%; S,10.2%.

Aqueous 36 percent formaldehyde (33 grams, 0.4 mole) was adjusted to pHof 10 by the addition of potassium carbonate in a 250ml. roundbottom3-neck flask. A total of 23 grams (0.075 mole) of 2,4-diami r 2 9 Q'-diethylphosphone)ethylthiol s-t riazihe was added. The mixture washeated to 60 C., which resulted in solution. Heat ing at 60C. wascontinued for a total of 12 hours. After filtering. the filtrate had20.4 percent total formaldehyde and 6.6'percent free formaldehyde (hence13.8 percent bound formaldehyde in N-hydroxy-methyl groups). Thereaction solution, 45 grams. represented an 82 percent conversion to 2,4 bis[bis(hydroxymethyllaminol-6-[2-(O, O-diethylphosphgnojethvlthiol-s-triazine.

In another trial. the charge in a 1-liter flask consisted of 145 grams(0.473 mole) of2.4diamino-6-[2-(0.0'-diethylphosphono)ethylthiol-s-trazine 197 grams(2.36 moles) of aqueous 36 pergnt formaldehyde and enough aqueous 50percent sodium hydroxide to maintTiirr tlTe 51 1 at 10. Heating at 60 C.resulted in solution, and that temperature was maintained forapproximately 6 hours. The resulting 340-gram solution had 18.99 percenttotal formaldehyde and 4.4 percent free formaldehyde (hence 14.6 percentbound foradded, with stirring, a solution of 35.2 grams (0.88 mole) ofmaldehyde in N-hydroxymethyl groups). The reaction solution, 60 percentactive, represented approximately 87 percent conversion to2,4-bis[bis(hydroxymethyl)amino]-6[2-(0,0'- diethylphosphono)ethylthio]Employing procedures similar to those described in Example I, cotton istreated with the thus-produced product, either alone or in combinationwith N ,N,N-tris(hydroxymethyl)- melamine, to render cottonflarne-retardant.

EXAMPLE VII Diethyl vinylphosphonate, 61.5 percent active by vinylanalysis, was made by following directions of G. Kosolapoff, J. Am.Chem. Soc, Vol. 70, page 1971 (1948). A total of 1,000 grams of thatmaterial (containing 3.75 moles of diethyl vinylphosphonate) was droppedinto 3 liters of a saturated solution of ammonia in ethanol at roomtemperature over a period of approximately 2 hours. Ammonia was slowlypassed into the solution during the next 5 days, by which time thestarting compound had disappeared almost completely (followed bythin-layer chromatography). Ammonia and alcohol were removed byvolatilization at room temperature. The crude residue, 830 grams,contained 2.5 moles of amine by titration with hydrochloric acid, andvinyl was absent. Approximately equal molar quantities were present ofdiethyl 2- aminoethylphosphonate (the 1:] adduct of ammonia andvinylphosphonate) and tetraethyl 2 ,2 iminobis(ethylphosphonate) (the1:2 adduct of ammonia and diethyl vinylphosphonate).

A total of565 grams (1.7 moles of total amine) of the crude residue wasadded dropwise over 30 minutes at a pH of 7.8 to a stirred suspension of228 grams (1.55 moles) of 2,4- diamino-fi-chloro-s-triazine in 2 litersof water at C. Then the pH was raised to 8.5 by the addition of 20 gramsof sodium carbonate. During the next 3 hours the pH was kept at 8.5 bythe addition of 110 grams of sodium carbonate, and the temperature waskept between 90 and C. At the end of that period, the reaction mixturewas filtered. The filter cake was washed and dried to yield 93.7 gramsof a solid which was mainly unreacted 2,4-diamino-6-chloro-s-triazine.

The filtrate was neutralized to pH 7 by means of 1 15 ml. of 15 percenthydrochloric acid. Then it was evaporated under diminished pressure toapproximately 750 ml., and the precipitate was filtered off. The filtercake (245 grams) was dissolved in 1 liter of boiling l-propanol, leavingan insoluble .residue weighing 7.5 grams. The propanol solution wasconcentrated to about 400 ml. and a total of 83.5 grams ofN'-'-[2-(0,0-diethylphosphono)ethyllmelamine melting at 219 to 220 C. wasobtained on crystallization.

Analysis: Calculated for C H N O P C, 37.3%; H, 6.55%; N, 28.9%; P,10.6%.

Found: C, 36.4%; H, 6.04%; N, 28.3%; P, 10.6%. The infrared spectrum wasconsistent with the assigned structure.

Solvent was evaporated from the filtrate remaining after thecrystallization, leaving a residue of 150 grams. The residue wascrystallized from 150 ml. of water. from which a total of 99 grams N .N-bis[2-(O.O'diethylphosphono)ethyl] melamine was obtained melting at 137to 138 C,

Analysis: Calculated for c u monyz C, 39.7%; H, 7.05%; N, 18.5%; P,13.7%.

Found: C, 39.9%; H,6.62%; N, 18.3%; P, 12.9%.

The infrared spectrum was consistent with the assigned structure.

The N -[2-(O,O'-diethylphosphono)ethyl]melamine grams, 0.414 mole) andaqueous 37% formaldehyde (167.5 grams, 2.07 moles) were mixed togetherand heated to 60 C. The pH was adjusted to 8 by the addition of 0.3 ml.of l-normal sodium carbonate. Both temperature and pH were kept constantfor a 5.5-hour period. Then the reaction mixture was kept at roomtemperature for 2 days. Upon analysis, the resulting aqueous solutionhad 4.55 percent free formaldehyde. Hence, each molecule of the melaminecompound had reacted with an average of 3.97 molecules of formal dehyde,and the principal reaction product was a tetrakis(hydroxymethyl)derivative of N -[2-(O,O'- diethylphosphono)ethyl]melamine.

Employing procedures similar to those described in Example I, thisproduct is employed, either alone or in combination with N ,N ,N-tris(hydroxymethyl)melamine, to render cotton flame-retardant.

The N ,N -bis[2-(O,O'-diethylphosphono)ethyl]melamine (100 grams, 0.22mole), aqueous 37 percent formaldehyde (89.2 grams, l.l moles), and 100grams of distilled water were mixed together and heated at 60 C. for 2hours after the pH had been adjusted to 8 by the addition of 0.4 ml. ofl-normal sodium carbonate. Heating at 60 C. was continued for anadditional 8.5 hours with the pH as high as 9.5. Then the reactionmixture was kept at room temperature for a day. Upon analysis, thethus-obtained aqueous solution had 9.95 percent total formaldehyde and3.04 percent free formaldehyde (hence 6.91 percent bound fonnaldehyde inthe form of N- (hydroxymethyl) groups). The mixture was filtered.Analysis of the filtrate showed that each molecule of the melaminecompound had reacted with an average of 2.9 molecules of formaldehyde.Hence the reaction product consisted principally of thetris(hydroxymethyl) derivative of N ,N -bis[2-(0,0-diethylphosphono)ethyl]melamine.

Employing procedures similar to those described in Example I, thisproduct is employed, either alone or in combination withN,N,N-tris(hydroxymethyl)melamine, to render cotton flame-retardant.

We claim:

1. A method for rendering a cellulosic substrate flame retardant whichcomprises treating said substrate with a compound of the formula:

*L l. LidJ. L

wherein R is lower alkyl, halogen-substituted lower alkyl or0,0'-di-lower alkylphosphono-substituted lower alkyl; each of R and R isalkylene of not more than 10 carbons; R is hydrogen, lower alkyl, or0,0-substituted-phosphonoalkyl of the fonnula (RO) P(O)R; R is hydrogenor lower alkyl; R is alkylene or alkanetriyl of not more than 10carbons; R is lower alkyl; Y is oxy, thio, imino or lower alkylimino;each or r, s, t, u, and v has a value of 0 or 1; with the provisos thatthe total carbons in R,R" and R is not more than 10; the sum of each ofr+s, r+u and t+u is l; r is 0 when R is phosphonoalkyl; and u is 0 and Ris hydrogen or alkyl when R is phosphonoalkyl; and Z is represented bythe formula:

wherein each of R and R is hydrogen or lower alkyl and n is an integerhaving a value of from 1 to 4.

2. A method according to claim 1 wherein said substrate is cotton andsaid compound is added in an amount sufficient to provide a phosphoruscontent, based upon the weight of the cotton, of from about 0.2 to about3 weight percent.

3. A method according to claim 1 wherein said compound is employed inadmixture with an organo-nitrogen compound.

4. A method according to claim 3 wherein said compound is employed inadmixture with an organo-nitrogen compound in an amount sufficient toprovide a nitrogen content of at least the value of the expression (3-2?wherein P is the weight percent phosphorus.

5. The product of the process of claim 2.

6. The product of the process of claim 4.

Patent No.

Dated March 972 lnventor(s) Tesoro et a1 It is certified that errorappears in the above-identified patent and that said Letters Patent arehereby corrected as shown below:

Column 1, line 66:

Column 2, line 10:

line

line

Column 9, line line Column lO,line

Column ll,line

Column l7,line

bis (hydroxymethyl)eminol6-yl" should read bis (hydroxymeth'yl)amino]s-=triazin-6-yl- The right side of formula (II) should read:

F" s "Q" .3 u N Z 57: The right side of Formula (III-B) should read C H2 68: {(Dfb" should read we f (Di- 5: The formula should read (-CO1\T\)8: The formula should read (-SO N\) 7'5: "herein" should read--wherein-- 6Q: IO- 196 4 9" should read --=-llO-l96 r-T-=- 58:"diethylphosphone) should read ---diethylphoSphono)-- UNITED STATESATENT @FMQE miimm'm or s EQMN Patent No. 3,650,670 mama March 23L 19??lnventofls) Tesoro et a1 2 It is certified that error appears in theabove-identified patent and that said Letters Patent are herebycorrected as shown below:

(CONTINUED) Column 18, line 4: "diethylphosphono)ethylthioJ" should read--diethylphosphono)ethylthio]-striazine-- Column 20, line 5: "R shouldread. 42

line 15: In his; formula "=C==N=" should read Signed and sealed this 9thday of January 1973.

(SEAL) Attest:

EDWARD D'LFLE'ICHER,JRo ROBERT GOTTSCHALK Attesting Officer Commissionerof Patents FORM PO-105O (10-69) USCOMM-DC 60376-P69 fr u.s. GOVERNMENTPRINTING OFFICE I969 o-ses-aaa UNITED STATES PATENT @IFMQE QElllQAlE omeomtomo Patent No. 3, 50, 70 Dated March 21, 1972 Invent0r(s) TEESOTQ eta1 It is certified that error appears in the above-identified patent andthat said Letters Patent are hereby corrected as shown below:

Column 1, line 66: "bis (hydroxymethyl)aminol6-yl" should read bis(hydroxymethyuamino'j s-triazin o-yl Column 2, line 10: The right sideof formula (II) should read:

line 57: The right side of Formula (III-B) should read line 68: (Di-"should read Column 9, line 5: The formula should read (-CON I line 8:The formula should read (-SO NQ Column lO,line 7'5: herein" should read--wherein-- Column ll,line 6Q: "no-196mg" should read ---llO-=l96U-T-Column 17,1ine 58: "di.e1;hylpho'sqohone) should read--dlethylphosphono)-- UNITED STATES PATENT @FFKCE summer OF Patent No. 3,650,6TO Dated March 21, 1.972

Inventor( TESOIO et all It is certified that error appears in theabove-identified patent and that said Letters Patent are herebycorrected as shown below:

(CONTINUED) Column 18, line 1-: "diethylphosphono)e'thylthioll" shouldread diethylphosphono)ethylthio]-s-triasine-- "R should read ---R Column20, line 5:

"=C==N=" should read line 15: In t1? formula Signed and sealed this 9thday of January 1973.

(SEAL) Attest:

EDWARD M.FLETCHER, JR. ROBERT GOTTSCHALK Attesting Officer Commissionerof Patents USCOMM-DC 60376-P69 U.S. GOVERNMENT PRINT NG OFFICE 1 I9690-366-334 FORM PO-105O (10-69)

2. A method according to claim 1 wherein said substrate is cotton andsaid compound is added in an amount sufficient to provide a phosphoruscontent, based upon the weight of the cotton, of from about 0.2 to about3 weight percent.
 3. A method according to claim 1 wherein said compoundis employed in admixture with an organo-nitrogen compound.
 4. A methodaccording to claim 3 wherein said compound is employed in admixture withan organo-nitrogen compound in an amount sufficient to provide anitrogen content of at least the value of the expression 6-2P wherein Pis the weight percent phosphorus.
 5. The product of the process of claim2.
 6. The product of the process of claim 4.